Hypervelocity jet producing system employing an impact cumulation process



Nov. 18, 1969 w c CQOLEY 3,478,966

HYPERVELOCITY JET PRODUCING SYSTEM EMPLOYING AN IMPACT CUMULATION PROCESS Flled July 25 1968 INVENTOR WILLIAM C COOLEY United States Patent US. Cl. 239-302 7 Claims ABSTRACT OF THE DISCLOSURE A device for producing hypervelocity pulsed fluid jets in which a pair of spaced moving carrier members is coated with a gel-like material. An impact head member is adapted to be propelled between the carrier members to impact the edges of the coating of charge material thereby generating a shock wave therein and converting the charge material into a fluid jet along a central plane between the carrier members. The impact head member is mounted for reciprocating motion and the carrier members are incrementally advanced to thereby present a fresh charge for each thrust of the impact head between the carrier members.

This application is a continuation-in-part of my copending application Ser. No. 728,273, filed May 10, 1968.

This invention relates to an apparatus and method for producing high velocity fluid jets by an impact cumulation process and, more specifically, to such apparatus and method which repetitively produces hypervelocity jets having different geometric shapes depending upon the physical conditions governing the impact process.

Cumulation may be defined generally as a concentration of energy into a small volume of fluid by the interaction between two material surfaces, at least one of which behaves as a fluid when the surfaces collide at an angle. A simple example is the formation of a water jet under a boat bow moving ahead faster than the boat when the hull planes at a small angle above the water surface. This phenomenon is caused by the hydrodynamic motion which produces a stagnation point on the hull a short distance back from the forward water line. Water streamlines above the stagnation streamline are forced to turn upward and reverse direction conserving their kinetic energy relative to the moving stagnation point and escaping forward with a velocity as much as twice the boat velocity.

In utilizing the impact cumulation process, it is desired to make a planar or curvilinear cut through materials such as metal, wood, plastic, rock, earth, concrete, etc. Such a cut can be made by a jet of fluid if the jet stagnation pressure is higher than the compressive strength of the material. Accordingly, it is the purpose of this invention to provide a method and apparatus for producing a sheet-like jet of fluid of high velocity which can be applied for cutting or other purposes. The sheet may be a thin planar sheet or it may be curved, circular or of such other shape for cutting material along a desired contour or to project the fluid in a desirable spatial configuration.

The main object of this invention is to provide an apparatus which can produce the cumulative effect by collision of materials in a planar geometry to form a pulsed planar jet of fluid which utilizes the kinetic energy of an impact member.

Another object of this invention is to provide a system for producing repetitive pulsed jet sheets of fluid of high stagnation pressure in the order of 50,000 to 200,000

p.s.i. or higher and having a velocity of at least 9600 ft. per .second, and which is particularly useful for rock breaking, cutting metal, wood, plastic, rock, earth, concrete and other materials.

Still another object of the invention is to provide a repetitive jet pulsing device employing a moving carrier member supporting a film of fluid material in conjunction with an impacting head member acting against the edges of the film.

It is a further object of this invention to provide a jet pulsing device for cutting material which employs a continuously moving carrier member having a fluid coating thereon and an impact member which is arranged to impact the edges of the fluid material for creating a shock wave therein, and to produce by cumulation a pulsed jet sheet of fluid having a high stagnation pressure.

It is a further object of this invention to provide a jet pulsing device employing a minimum of parts which can be constructed in a simple and economical manner for producing a reliable and continuous operation.

In accomplishing the aforesaid objects of this invention, one embodiment utilizes spaced parallel belt members or carriers arranged on suitable supply and take-up reels and in which each belt rides along an inside surface of corresponding spaced parallel walls of a housing member. Each of the carriers is coated with a fluid charge material, for example, a plastic or gelatinous or other relatively weak solid or gel material, such that each coating opposes the other in spaced parallel relationship. An impact hamme'r member is arranged adjacent the housing and, under the control of a suitable force, enters the housing between the belt carriers such that the hammer rams or impacts against the edges of the charge coating on each of the belt carriers. The impact hammer is propelled at a high velocity so as to impact simultaneously the two edges of the gelatinous material producing a shock wave in each coating or charge, and forcing the charge to flow hydrodyriamically toward the center plane of the housing where the two charges meet forming a cumulative planar jet at a velocity of about twice the shock wave velocity in the charge material.

Other objects and advantages will become apparent from a detailed study of the following specification and drawings, in which:

FIG. 1 shows an elevated cross-section showing one embodiment in which the charge material is precoated on parallel spaced carriers being supported on supply and take-up ree'ls according to the principles of this invention;

FIG. 2 is a cross-sectional view taken along lines 22 of FIG. 1;

FIG. 3 illustrates schematically another embodiment employing the principles of this invention in which the carrier for the charge material is coated during the operation of the device;

FIG. 4 illustrates in cross-section the different shapes of the coating of charge material on the carrier;

FIG. 5 shows another embodiment employing the principles of this invention in which a pair of spaced parallel discs is utilized as the moving carrier members for the charge material; and

FIG. 6 shows a cross-sectional view along the lines 55 of FIG. 4.

Referring now to FIG. 1, there is shown a housing frame member 2 of generally square configuration having opposed parallel inside surface walls 4. Positioned above the housing 2 is a pair of supply reels 6 having wound thereon carrier belts or webs 8 composed of a high strength flexible material. Each of the carriers is passed over the inside surface walls 4 of the housing 2 and taken up on suitable take-up reels 10, as shown. Each of the carrier strips 8 is precoated with a layer of charge material which may be a plastic, a gelatinous, or some such other relatively weak solid or gel charge material. By way of one example of such a material the invention may employ glycerin.

In FIG. 2 there is shown an impact head member or ram 14 supported for axial movement through the housing 2 by the guide channel member 16, as shown. The member 14 is connected to a suitable reciprocable drive means 18 for driving the impact member 14 through the interior of the housing 2 and past the carrier strips 8. As shown in FIG. 2, the take-up reels are connected to a motor so that the carrier strips 8 may be incrementally advanced along the side walls 4 of the housing 2, which will be more fully explained below.

The method of operation according to this invention is as follows: When the carrier strips 8 are positioned against the side walls 4 with their respective coatings of charge material 12 opposing each other as shown in FIG. 1, the device is ready for operation. At this moment the impact member 14 is accelerated by the drive means 18 along the guide channels 16. The impact head 14 is of substantially the same dimensions as the interior of the housing 2, the lateral or wide dimension of the impact head 14, however, being sufiicient to clear the wall surfaces 4 as well as the moving carrier strips 8 but not the coating of charge material 12. When the impact head 14 is propelled along the guide channel 16, it will impact simultaneously on the two edges of the charge material 12 on each of the strips 8. This impact produces shock waves in each layer of the charge and the two layers of shocked charge material flow hydrodynamically toward the center plane of the housing 2 where they meet and form a cumulative planar jet at a velocity of about twice the shock wave velocity set up in the charge material by the impact from the head 14. The planar jet pulse leaves the housing 2 as shown by the arrows in FIG. 2 and thereafter acts on the workpiece to be cut. At this time the impact hammer 14 is withdrawn from the housing along the channels 16 and the motor 20 is activated by suitable timing means 22 to advance both carrier strips 8 along the side walls 4 of the housing 2 thereby presenting a fresh charge for the next operation. In this manner the impact hammer 14 can be driven in a reciprocating manner at high speeds and the motor 20 can be operated to incrementally advance the strips 8 along the side walls 4 in timing relationship with the drive means for the impact hammer 14.

Referring to FIG. 3, there is shown another embodiment in which the carrier strips 8 are not precoated with the charge material 12. The carrier strips are in the form of an endless belt 8 as shown in which a portion of the belt passes through a bath of gel-like charge material 12' contained in a suitable vessel 24. The carrier belts 8' are supported on suitable rollers, one of which is driven by a motor 20, to thereby advance the belt 8 in an incremental manner as above described. As each of the carrier strips 8' moves in the direction indicated by the arrows and passes through the vessels 24 to pick up a coating of gel charge material on each side thereof, one side of the carrier strip is scraped by a scraping blade 28 provided for this purpose to clear the inside surface of each of the carriers 8' for passage along the surface walls 4 of the housing 2. Positioned opposite the blades 28 are blades 28 which act to shape the coating 12 according to a given configuration. For example, as shown in FIG. 4 the coating 12 may be rectangular or approaching triangular in shape depending on the angle that the blades 28 are maintained with the flat surface of the belt 8'. The system, as shown in FIG. 3, operates in the same manner as that described for the embodiment shown in FIGS. 1 and 2 with each of the carriers 8' advancing incrementally along the inside surface walls 4 of the housing 2 in cooperation with the reciprocating ram 14.

A further embodiment shown in FIG. 4 employs a pair of spaced, parallel disc members 26 which are fixedly supported on a rotatable shaft 28, itself supported above the vessel 30 containing a supply of the gel charge material 12. Mounted above the discs is a rotatable impact member 32 which is adapted to swing between the discs such as to impact the edges of the gel material formed on the discs as a result of their passing through the charge bath 12. Again, a motor 18 is provided for rotatably driving the impact member 32 between the discs 26, and a timer control means connects both the motor 18' for driving the impact member 32 and the motor 20" for incrementally rotating the discs 26 through the bath 12. Upon impact by the impact head 32 with the edges of the gel charge formed on the discs 26, a shock wave is set up in the charge material and the cumulative sheetlike jet is formed between the discs 26 in the manner above described.

It is to be understood that the sheet jet pulse formed by the impact of the head member 14 can be varied in shape, that is, it may be curved, circular or of some such other shape for the purpose of cutting a workpiece along a desired contour, or to project the fluid jet in a desirable spatial configuration. The shape of the emitted or extruded jet is controlled by the shape of the impact surface of the head member 14. As shown in the drawings, this impact surface is flat; however, the same surface may be curved or shaped to some predetermined design to impart a corresponding shape to the extruded pulse jet.

That which is claimed is:

1. In a device for discharging hypervelocity pulsed fluid jets, the combination comprising, a pair of spaced parallel carrier means, means for incrementally advancing said carrier means simultaneously, said carrier means having a coating of fluid charge material, an impact member movably mounted adjacent said carrier means, means for propelling said impact member between said carrier means, whereby said impact member impacts the respective edges of said coating of charge material on said carrier means for generating a shock wave therein and converting said charge material into a fluid je't along a central plane between said carrier means.

2. In a device for discharging hypervelocity pulsed fluid jets, the combination comprising, a pair of spaced carrier strips, means for moving said carrier strips simultaneously, a housing having a pair of spaced wall surfaces for supporting said carrier strips, said carrier strips having a coating of fluid charge material on the side opposite the side supported by said wall surfaces of said housing, an impact member movably mounted adjacent said carrier strips, means for propelling said impact member between said carrier strips, whereby said impact member impacts the respective edges formed by said coating of charge material on said carrier strips for generating a shock wave therein and converting said charge material into a fluid jet along a central plane between said carrier strips.

3. A device according to claim 2, wherein each of said carrier strips is in the form of an endless belt, a vessel means containing said fluid charge material through which a portion of each of said belt passes to thereby pick up said coating of fluid charge material.

4. In a device according to claim 3, wherein a scraping means is positioned adjacent said vessel for cleaning one surface of said belt.

5. In a device according to claim 3, wherein a scraping means is positioned adjacent said vessel for shaping said coating of fluid charge material for a given dimension.

6. In a device according to claim 2, wherein said carrier strips are supported on a supply reel means and a take-up reel means.

7. In a device for discharging hypervelocity pulsed fluid jets, the combination comprising, a pair of rotatably mounted spaced disc members, a vessel containing a fluid charge material positioned beneath said disc members for allowing a portion of said members to be immersed in said charge material, means for simultaneously 5 6 moving said members through said charge material to References Cited provide a coating of fluid charge material on said disc UNITED STATES PATENTS members, an impact member movably mounted adjacent said disc members, means for propelling said impact 3 fgfifi member between said disc members whereby said impact 5 3412554 11/1968 Voitsekhousky g i" 5 member impacts the respective edges formed by said n coating of charge material on said disc members for SAMUEL W. ENGLE, Primary Examiner generating a shock Wave therein and converting said charge material into a fluid jet along a central plane between said disc members. 10 898; 124-11; 239101, 327 

